Of skuas there are but six species, two of which inhabit the southern hemisphere, and breed on the confines of the antarctic regions. The others belong to the northern half of the globe, and range in summer to the arctic regions. These four are all claimed as members of the British avifauna, but only two species need be fully described in this work. The skuas are gull-like birds, very strong on the wing, and swift flyers; and, like the gulls, they have a variety of feeding-habits, and are both the vultures and hawks of the sea. In the skuas there is more of the hawk and not so much of the vulture. Their predatory habits, extreme violence in attack, and readiness to take and destroy their feathered fellow-creatures and toilers of the deep when the occasion offers, have won them a reputation among birds similar to that of a pirate among men--the lawless rover of the sea, who is without compunction, and whose hand is against every man. In shape and general appearance the skuas are gull-like; they differ chiefly from the gulls in the form of the beak, which is straight for two-thirds of its length, and for the rest curved into a hook, as in the raptorial birds; and in the form of the tail, which is cuneiform, with the two centre feathers projecting beyond the others. In the gulls the tail-feathers are of equal length; while the terns, at the other end of this order of birds, have sharply forked tails like the swallow. The great skua, or bonxie, as it is called by the Shetlanders, is the largest of the family. Except during the breeding season it is a solitary bird, oceanic in its habits, roaming far and wide over the waters in quest of food, its visits to land being restricted to rocky island coasts. Like the marine gulls, it feeds on dead fish found stranded or floating on the water, and on dead animal matter of all kinds, and also catches fish by pouncing on them as they swim near the surface. But it prefers to watch the movements of the other fishing-birds, which it follows and associates with to rob them of their prey. The herring-gull and lesser black-back may be frequently seen pursuing a tern or kittiwake to take from it the fish it has just captured; but these would-be robbers are not very successful--the chased tern, or small gull, in most cases proves too quick for them. These are like the merest mock chases and playful interludes in the day’s work compared with the sudden, furious onslaught of the bonxie. The swiftest gull or tern cannot escape from him; he can turn as quickly as a swallow, and keep close to his victim in all his doublings, until the chased bird in his terror disgorges the fish he has just swallowed. The skua stays his flight to pick up the falling morsel, and the chase is over. Besides robbing the birds of their prey, he is also a bird-killer, making his deadly attacks on the sickly or wounded, and on the young in the breeding season.